1. Field of the Invention
The present invention relates generally to medical lasers and, more particularly, to methods of preventing damage to medical lasers during startup.
2. Description of Related Art
Medical lasers find application in surgical and dental procedures. Laser power transmitted from a fiber tip can be used to treat (e.g., cut) biologic tissue such as skin, bone, dental tissue and the like. Various kinds of contamination of the fiber output can occur during this process. Water, blood, bits of tissue and even dust may accumulate on the fiber tip during use. Typically these impurities are burned off by action of the laser.
As one example, FIG. 1 illustrates a dental handpiece 10 that receives laser power from a laser module disposed in a laser housing and connected to the handpiece by a fiber optic waveguide (the laser module, laser housing and fiber optic waveguide are not shown in FIG. 1) that terminates in a fiber tip 15 that can emit laser energy to perform medical treatment. A more detailed view of the filter tip portion of the handpiece of FIG. 1 is illustrated in FIG. 2. After an extended period of non-use, particles of debris 20 that collect on the surface of the fiber 15, debris normally burned off by laser energy emitted from the fiber, may adhere to the fiber.
After such a period of non-use, suddenly transmitting a high level of laser power, corresponding, for example, to the opening of a shutter to generate a pulse of laser power, can cause the debris to rapidly and undesirably absorb a large amount of energy that can result in a rapid rise in temperature of the debris and the fiber tip. As illustrated in FIG. 3, this rapid temperature rise can trigger a sudden burst of heat and/or smoke 25 resulting from sudden burning of the debris 20 and can generate one or more acoustic shock waves 30 that can propagate along the fiber 15 toward the components of the handpiece 10 and into the laser housing and laser module with the potential that these components can be damaged.
A need exists in the prior art to ameliorate the effect of initial startup of a laser treatment device after an extended cooling-off period.